Fulham midfielder Joao Palhinha was forced off in Sunday's 3-2 victory over Brentford in Philadelphia.
Competing in the inaugural Premier League Summer Series, Fulham took the lead in the third minute thanks to Harry Wilson's curling effort.
After seeing their early advantage cancelled out by Yoane Wissa, the Cottagers moved back in front through Bobby Decordova-Reid.
Carlos Vinicius added a third for Marco Silva's side, before Brentford's Vitaly Janelt rounded off the scoring in an entertaining affair.
Despite enjoying a successful outing, Fulham's 3-2 victory was overshadowed by a 'serious-looking' injury to Joao Palhinha.
There are fears that he has disclosed his shoulder after he was forced off on the stroke of half time with his arm supported in a makeshift sling by his shirt.
Speaking after the game, Silva told reporters: "Unfortunately it doesn't look good. He's probably dislocated his shoulder.
"Tomorrow [Monday] he is going to do a scan and it will be more clear. Let's hope it's not another long-term injury for us."
The Portuguese midfielder has been linked with a move away from Craven Cottage this summer, amid interest from Liverpool and West Ham United.
The Hammers have already had a £45m bid rejected for Palhinha, who has a contract until the summer of 2027 with an option to extend by a further year.
With the 28-year-old waiting set to have a scan today, a potential departure could depend on the extent of the injury.
After arriving from Sporting Lisbon last summer, Palhinha quickly established himself in the Fulham side, starting all 35 of his Premier League appearances.
The Cottagers will continue their preparations for the new season on Wednesday when they face Aston Villa at the Exploria Stadium in Orlando. body check tags ::